{ lib, config, ... }:
with lib;
{
  options = { 
    blocks = mkOption {
    type = types.attrsOf (
      types.submodule {
        options = {
          displayName = mkOption {
            type = types.str;
            description = "The display name of the block.";
          };
          properties = {
            ## Mining properties

            # .strength(float destroyTime, ?) 
            hardness = mkOption {
              type = types.float;
              default = 1.0;
              description = "The block's destroy time (hardness).";
            };
            # .strength(?, float explosionResistance)
            resistance = mkOption {
              type = types.nullOr types.float;
              default = null;
              description = "The block's explosion resistance.";
            };
            # requiresCorrectToolForDrops()
            requiresTool = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block requires the correct tool to drop.";
            };

            ## Physical properties

            # noCollision()
            noCollision = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block has no collision.";
            };

            # noOcclusion()
            noOcclusion = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block has no occlusion.";
            };

            # dynamicShape()
            dynamicShape = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block has a dynamic shape.";
            };

            # forceSolidOn()
            forceSolidOn = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block is forced to be solid on all sides.";
            };

            # pushReaction(PushReaction)
            pushReaction = mkOption {
              type = types.enum [ "NORMAL" "DESTROY" "BLOCK" "IGNORE" "PUSH_ONLY" ];
              default = "NORMAL";
              description = "The block's reaction to being pushed by pistons.";
            };

            # offsetType(BlockBehaviour.OffsetType)
            offsetType = mkOption {
              type = types.enum [ "NONE" "XYZ" "XZ" ];
              default = "NONE";
              description = "The block's offset type.";
            };

            # replaceable()
            replaceable = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block is replaceable; e.g. like tall grass or snow layers.";
            };

            ## Movement

            # friction(float)
            friction = mkOption {
              type = types.float;
              default = 0.6;
              description = "The block's friction.";
            };

            # speedFactor(float)
            speedFactor = mkOption {
              type = types.float;
              default = 1.0;
              description = "The block's speed factor.";
            };

            #jumpFactor(float)
            jumpFactor = mkOption {
              type = types.float;
              default = 1.0;
              description = "The block's jump factor.";
            };

            ## Visual
            #mapColor(MapColor) & mapColor(DyeColor) & mapColor(closure)
            mapColor = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = ''
                The block's map color. For dyecolor, use dye:<color>, map:<color>.
                To specify a closure, use closure:<fqdn>. For example, to reference the GetMapColor(<block>) method of a class, use closure:com.example.MyBlock::getMapColor.
              '';
            }; 

            #lightLevel(ToIntFunction<BlockState>)
            lightLevel = mkOption {
              type = types.nullOr (types.oneOf [ types.int types.str ]);
              default = null;
              description = ''
                The block's light level. Can be a constant integer (0-15), or a path method with (BlockState) -> Integer, e.g. closure:com.example.MyBlock::getLightLevel.
              '';
            };

            #noTerrainParticles()
            noTerrainParticles = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block has no terrain particles.";
            };

            #isViewBlocking(BlockBehaviour.StatePredicate)
            isViewBlocking = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = "Whether the block is view blocking. Provide a path to a BlockBehavior.StatePredicate method, e.g. closure:com.example.MyBlock::isViewBlocking.";
            };

            #isSuffocating(BlockBehaviour.StatePredicate)
            isSuffocating = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = "Whether the block is suffocating. Provide a path to a BlockBehavior.StatePredicate method, e.g. closure:com.example.MyBlock::isSuffocating.";
            };
            ## Sound

            sounds = mkOption {
              type = types.str;
              default = "STONE";
              description = "The name of the vanilla SoundType constant to use.";
            };

            instruments = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = "The name of the vanilla Instrument constant to use.";
            };

            ## Loot
            noLootTable = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block has no loot table.";
            };
            lootFrom = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = "A Supplier<? extends Block> that provides the loot table for this block. Provide a path to a method that returns a Block, e.g. closure:com.example.MyBlock::getLootTable.";
            };

            ## Miscellaneous
            randomTicks = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block receives random ticks.";
            };

            ignitesByLava = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block can be ignited by lava.";
            };

            liquid = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block is a liquid.";
            };

            isValidSpawn = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = "BlockBehaviour.StateArgumentPredicate<EntityType<?>> that determines whether this block is a valid spawn point for the given entity type. Provide a path to a method that returns a boolean, e.g. closure:com.example.MyBlock::isValidSpawn.";
            };

            air = mkOption {
              type = types.bool;
              default = false;
              description = "Whether the block is air-like";
            };

            requiredFeatures = mkOption {
              type = types.listOf types.str;
              default = [ ];
              description = "A list of required features for this block to be available. Written as <modid>:<feature>.";
            };
          };
          customClass = mkOption {
            type = types.nullOr types.str;
            default = null;
            description = ''
              Path (relative to this mod.nix) to a hand-written Java file whose
              public class extends the generated "Base''${className}" block class.
              When unset, snowy generates one flat, concrete block class instead.
            '';
          };
          /*
            states = {
              "Integer:power" = {
                min = 0;
                max = 15;
                default = 0;
              };
              "Boolean:lit" = {
                default = true;
              }
              "Enum:facing" = {
                enum = "net.minecraft.world.level.block.state.properties.BlockStateProperties.FACING"
              }
              
            }
          */
          states = mkOption {
            type = types.attrsOf {

            };
          };
          customModel = mkOption {
            type = types.bool;
            default = false;
            description = ''
              When true, snowy still generates this block's blockstates.json
              (pointing at "<namespace>:block/<path>" as usual), but expects a
              hand-written models/block/<path>.json to already exist there
              instead of generating one from textures. Mutually exclusive with
              textures.
            '';
          };
          item = {
            enabled = mkOption {
              type = types.bool;
              default = true;
              description = "Whether to register a BlockItem for this block.";
            };
            texture = mkOption {
              type = types.nullOr types.str;
              default = null;
              description = ''
                Flat 2D item icon (relative to textures/item/, no extension).
                When unset, the item renders the block's 3D model instead.
                Mutually exclusive with item.customModel.
              '';
            };
            customModel = mkOption {
              type = types.bool;
              default = false;
              description = ''
                Like the block-level customModel: expect a hand-written
                models/item/<path>.json instead of generating one.
                Mutually exclusive with item.texture.
              '';
            };
          };
          blockEntity = mkOption {
            type = types.nullOr (
              types.submodule {
                options = {
                  class = mkOption {
                    type = types.str;
                    description = ''
                      Path (relative to this mod.nix) to a hand-written Java file
                      whose public class extends the generated
                      "Base''${className}Entity" block entity class.
                    '';
                  };
                  ticker = {
                    client = mkOption {
                      type = types.bool;
                      default = false;
                      description = "Whether this block entity ticks on the client.";
                    };
                    server = mkOption {
                      type = types.bool;
                      default = false;
                      description = "Whether this block entity ticks on the server.";
                    };
                  };
                };
              }
            );
            default = null;
            description = "The block entity attached to this block, if any.";
          };
        };
      }
    );
    default = { };
    description = ''
      The blocks this mod registers, keyed by full registry name
      ("<modid>:<path>").
    '';
  };
  };
}